Refactoring

• Refactoring is a technique to restructure code in a disciplined way.
• A change to the system that leaves its behavior unchanged, but enhances some nonfunctional quality - simplicity, flexibility, understandability, performance.

Like Design Patterns, there is a long list of well-known refactorings:

• Add Parameter
• Change Reference to Value
• Change Value to Reference
• Decompose Conditional
• Duplicate Observed Data
• Encapsulate Collection
• Encapsulate Downcast
• Extract Class
• Extract Interface
• Extract Method
• Extract Subclass
• Extract Superclass
• Hide Delegate
• Hide Method
• Inline Class
• Inline Method
• Inline Temp
• Many more ...
• http://www.refactoring.com